By Futurist Thomas Frey

Physicist Kip Thorne once posed a question that should keep us all awake at night: “1000 years from now, what things will be possible and what things won’t?” It’s a profound challenge to our assumptions about reality itself. But here’s an even more unsettling question: how much of what we believe today—what we build policies around, invest billions in, teach our children—is simply wrong?

Samuel Arbesman’s book “The Half-Life of Facts” quantifies something we intuitively suspect but rarely confront: everything we know has an expiration date. Scientific facts, medical knowledge, historical understanding—all of it decays over time, replaced by better information, corrected understanding, or entirely new paradigms. And the decay is measurable, predictable, relentless.

The implications are staggering. We’re making trillion-dollar decisions, shaping civilizations, and planning futures based on knowledge that we can statistically predict will be proven wrong. We just don’t know which parts yet.

The Mathematics of Wrongness

Arbesman discovered that facts decay at measurable rates, following patterns similar to radioactive decay—hence “half-life.” In some fields, half of what we know will be overturned or significantly modified within a decade. Medical knowledge has a half-life of roughly 45 years, meaning half of what doctors learned in medical school will be obsolete or incorrect by the time they retire.

Think about that. Your doctor’s foundational medical training includes information that’s provably false—we just don’t know which half yet. The antibiotics prescribed routinely? Many will eventually be recognized as overused or misapplied. The nutritional advice? Much of it will be revised or reversed. The diagnostic criteria? Continuously updated as we understand conditions better.

This isn’t failure—it’s how knowledge works. We learn, we refine, we correct. But we build entire systems around current knowledge, and those systems ossify while the knowledge beneath them crumbles.

The Infrastructure of Obsolete Ideas

Our world is framed around assumptions that may already be wrong but persist because infrastructure is expensive to change.

Consider urban planning. Cities worldwide are built around assumptions about transportation, work locations, and human density patterns. But remote work, autonomous vehicles, and changing social preferences are invalidating those assumptions. The 20th-century city—optimized for commuting workers in personal vehicles—may be solving problems that no longer exist while ignoring problems we haven’t fully recognized yet.

Or education systems, still largely organized around industrial-era assumptions: standardized curricula, age-based cohorts, centralized facilities, knowledge transfer from expert to novice. But learning science has evolved dramatically. We understand neuroplasticity, personalized learning, distributed intelligence, and lifelong education differently now. Yet we’re still building schools for a model of learning that’s increasingly obsolete.

Healthcare infrastructure assumes disease patterns, treatment modalities, and care delivery systems based on decades-old data. We’re building hospitals for a medical paradigm that’s already being replaced by preventive care, genomic medicine, and continuous monitoring. By the time these facilities are finished, the assumptions they’re built on will be outdated.

Energy grids, financial systems, legal frameworks, agricultural practices—all built on foundations of knowledge that’s continuously eroding beneath them. We’re living in structures built on facts that are expiring in real-time.

The Dangerous Persistence of Confident Ignorance

The problem isn’t just that we’re wrong—it’s that we’re confidently wrong. We teach obsolete knowledge with certainty. We regulate based on outdated science. We invest based on assumptions we haven’t revisited in decades.

Take nutrition science. For years, we demonized fats, then carbohydrates, then specific ingredients. Entire food industries rose and fell based on scientific consensus that later reversed. But during each phase, we acted with absolute confidence—creating guidelines, shaming non-compliant eaters, building billion-dollar industries around temporary truths.

Or consider economics. How many financial models, investment strategies, and policy decisions are built on economic theories that we’ll eventually recognize as incomplete or wrong? We can’t know in advance, so we proceed with confidence while the foundations shift beneath us.

The danger multiplies when wrong knowledge becomes institutional. Once incorporated into regulations, professional standards, or educational curricula, incorrect information becomes incredibly difficult to dislodge. The system develops antibodies against correction. Careers are built on existing paradigms. Industries profit from current models. Institutions resist change that would require admitting previous error.

Thorne’s Question and the Limits of Possibility

When Kip Thorne asks what will be possible in 1000 years, he’s really asking: what are the actual limits of physical reality versus what are merely limits of our current imagination and understanding?

We assume certain things are impossible—faster-than-light travel, reversing entropy, consciousness transfer, time manipulation. But how many of these assumptions are fundamentally true versus artifacts of our incomplete knowledge? A physicist in 1900 would have confidently declared many things impossible that are now routine. Nuclear energy, quantum computing, genetic engineering—all would have seemed like fantasy, violations of known physical law.

The terrifying possibility is that we’re making the same category errors today. We’re declaring things impossible based on physics we’ll later recognize as incomplete. We’re limiting our ambitions based on constraints that aren’t actually constraints, just current ignorance.

Conversely, we might be assuming certain things are inevitable—interstellar colonization, artificial general intelligence, fusion energy—that turn out to be genuinely impossible for reasons we haven’t discovered yet. Our entire civilizational roadmap might be aimed at destinations we can never reach.

Living in the Transition

So how do we function in a world where knowledge expires continuously? How do we build systems that can adapt as facts decay?

Epistemic humility becomes critical. Every plan, policy, and investment should include explicit acknowledgment of uncertainty. “Based on current knowledge” isn’t a disclaimer—it’s a fundamental truth about every decision we make. Systems should be designed for revision, not permanence.

Rapid iteration over long-term planning. When knowledge decays predictably, long-term plans based on current facts become increasingly unreliable. Better to build systems that can pivot quickly than to commit to elaborate plans built on facts with short half-lives.

Meta-knowledge over specific knowledge. Instead of teaching facts, we should teach how to evaluate facts, how to recognize when knowledge is decaying, how to update beliefs when evidence changes. The skill isn’t knowing—it’s learning how to know differently when necessary.

Reversible decisions. Whenever possible, make choices that can be undone when underlying assumptions prove wrong. Irreversible commitments—nuclear waste storage, urban infrastructure, constitutional amendments—should face extraordinary scrutiny because we’re committing future generations to decisions based on knowledge that will expire.

Diversity of approaches. When we don’t know which facts will decay first, pursuing multiple strategies simultaneously hedges against being wrong. Monocultures—of ideas, systems, or solutions—are vulnerable to paradigm shifts.

Final Thoughts

We are, all of us, operating with provisional knowledge that we treat as permanent truth. The ground beneath our feet is constantly shifting, but we build as if it were solid.

Kip Thorne’s question challenges us to distinguish between limits of reality and limits of imagination. Arbesman’s book reminds us that our current understanding has a measurable expiration date. Together, they suggest profound humility: we know less than we think, and much of what we do know will be proven wrong.

The question isn’t whether our knowledge will decay—that’s inevitable. The question is whether we’ll build systems flexible enough to survive their own foundational assumptions being proven false.

Because they will be. We just don’t know which ones yet.

Related Links:

The Half-Life of Facts by Samuel Arbesman

Kip Thorne on the Future of Physics

How Scientific Knowledge Changes Over TimeRetry

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